Correction device for repeater compasses



E. A. SPERRY.

CORRECTION DEVICE FOR REPEATER COMPASSES.

APPLICATION FILED IRA-V17. 191T- 1,403,062, Patented Jan. 10, 1922.

4 SHEETHIIEET INVEN TOR 17 [mar/5. 5perzy.

E. A. SPERRY.

CORRECTION DEVICE FOR REPEATER COMPASSES. APPLICATION FILED my". 19H.

1,403,062. Patented Jan. 10, 19221 4 SHEETS-SHEET 2- E. A. SPERRY.

CORRECTION DEVICE FOR REPEATER COMPASSES.

APPLICATION FILED null. 191:.

1,403,0 2, Patented Jan. 10,1922.

4 SHEETS-SHEET 3.

. when used on moving objects such as ships.

UNITE!) STATES PATENT OFFICE.

mm A. SPEEDY, OF BROOKLYN, NEW YORK, ASSIGNOB T0. SPEEDY GYBOSGOPECOMPANY, OI'BMOKLYFI', NEW YORK, A CORPORATION 01 NEW YORK.

(lORBEOTION DEVICE IOB REPEATER COIPASBES.

Toall whom it. may concern.-

Be it known that I, Emma A. Smear, a citizen of the United States ofAmerica, residing at 1505 Albermarle Road, Brook 11, in the county ofKings and State of ew York, have invented certain new and usefulImprovements in Correction Devices for Beeater Compasses, of which. thefollowing is a specification.

This invention relates to devices for correcting the readings ofg'yroscopic compasses This application has certain features incommonwith my copending application on G roscopic navigational apparatus,Serial o. 634,595, filed June 21, 1911, patented February 5, 1918,Patent No. 1,255,480, and to that extent is'a continuation thereof.

As explained in said application, a deflection of a g roscopic compassoccurs on ships which is adected by at least three variables; first, thespeed of the ship; second, the heading or course of the ship, and third,the

latitude of the ship.

The relation between these variables is expressed in the followingequation:

Kcos H tan dulum having an eccentric connection with the compass toimpart ballistic thereto and at the same time suppress the oscillationthereof, a third correction is needed as explained in said application,which is expressed by the following equations Where D represents thetotal correction.

A dos H where A and B are constants of the individual instruments.

Referrin to the drawings in which what I now consider to be thepreferred forms of my invention are shown:

Fig. 1 is a plan view of one form of dummy or repeater compassconstructed ac- Bpwiflmion of Letter! Patent Patented Jan. 10, 1922.Application fled lay 17,

1917. serial Io. 100,100.

Fig. 3 is a side elevation, partly in sec-- tion, thereof, the cardbeing shown as turned through 90 from Fig. 2 to show the inclination ofthe cosine ring.

Fig. 4 is a plan view of the form of master or gyroscopic compassadapted to be used wlt the form of repeater compass shown in Fig. 1. a V

Fig. 5 is a corresponding view of the master compass designed to be usedwith the repeater compass of Fig. 2.

Fig. 6 is a transverse sectionof the correction device on an approximateline 66 of Fig. 3.

'Fig. 7 is a rear elevation of said device.

Fig. 8 is a wiring diagram of the form of the invention shown in Figs.2, 3 andvb.

Fig. 8' is a wiring diagram of a different form of the invention.

F ig. 9 is a diagrammatic view of a second orm'of the correction deviceeither for a repeater or dummy compass or for a gyrosco ic vcompass.

ig.: 10 is a detail of a portion of the mechanism shown in Fi 5.

According to. this invention instead ofapplying the correction directlyto the master compass I prefer to use a separate dummy or re eatercompass on which the correction to a -plied may becomputed or indicated.Sucli trated in Fig. 1 in which the rotatable card 1 is adapted to beset. to correspond to the readings of the master compass 2 shown in Fig.4. The settin of the card may be cfan instrument is illus- 1 fected byhand if esired, through a handle 3 which is shown as secured to a stem 4on the inner end of which is a crown gear 5 ads ted to mesh with gear 6.The said gees may be secured to the underside of the card 1 so that onrotating the handle the card may be. set in a predetermined position.

In addition to or in place of said hand setting means I prefer toprovide an automatic means for maintaining the card ih synchronism withthe master compass. For

this purpose I have-shown a step-by-step ioo repeater motor 7 adapted tobe driven from a plurality of contacts 8 on the master com pass, thesaid contacts being in the form of a transmitter, adapted to excite thestationary field windings 9 of the repeater motor in succession in thewell known manner (see Fig. 8). Said repeater motor is shown as providedwith a pinion 10 meshing with a gear 11 on the shaft of which is mounteda second pinion 12 meshing with the aforesaid gear 6. If desired, asecond card 13 may be provided to rotate at much higher speed than card1 for indicatingaccurately small subdivisions. The card 13 is shown asdriven from the pinion 114 meshing with idler 115 which in turn isdrivenfrom pinion 12.

In order to effect the correction I prefer to shift the relativelystationar member or ring '14 which carries the in ex mark or markings 15on which the aduations 16 on the compass card are rea able. It is, ofcourse, obvlous that the graduations ma be borne by either. one or bothof the mem ers 1 or 13. The ring 14 bears the markings or indices 15which may serve as the real or apparent lubbers line of the ship. Meansare provided to shift the said ring an amount sufficient to correct forthe error due to the speed and latitude of the shi In order to so shiftthe said ring I may employ any suitable linkage to introduce thecorrections in whole or in part indicated in the above equation. Oneform of such linkage is shown in Fig. 9, this form being as illustratedby the aforesaid application and being more or less diagrammaticallyillustrated. The resultant movement from the several pieces of mechanismemployed to perform the several component corrections is imparted to abar 120 hereinafter sometimes termed, forconvenience, a correctiondevice, a correction member, or a device .for indicating compasscorrections. The speed correction varies as a direct function of thespeed, as indicated in the formula, and is brought about by means of apointer 121 whic is pivoted at 21 and cooperates with a speed scale 20'.This pointer may either be adjusted by hand, after the speed has beenascertained in any known manner, or may be automatically adjusted bybeing connected to the pointer 122 of a tachometer 123 driven,preferably in one direction only as indicated by the ratchet 124 fromthe ships engine or turbine 125. Pointer 121 is connected through a link139 to an upright lever 138, hereinafter referred to.

The course correction varies as ,a trigonometrical function (the cosine)of the meridional component of the course or heading, as indicated inthe equation, and is introduced by means of a bent lever 126 pivotallysupported at 127said lever being suitably connected to and controlled bya movable indicator 128 of course or heading which may or may not beactuated directly as a part of the gyro-compass. The said lever is shownas connected to a link 129 having a pin or roller 130 working in groovedring 131 which is mounted to move with the compass card and is arrangedslightly eccentric thereto, whereby movement of the card about itscenter causes the arm to swing about pivot 127 on account of theeccentricity of the ring. The latitude correction is also atrigonometrical function (the cosine) of the latitude, as indicated bythe formula, and is performed or introduced by the pointer 132 andcooperating with a latitude scale 134 raduated according to cosines oflatitude. he latitude correction is impressed upon the other twocorrections before they reach the bar 120 by means of the link 135,which connects the bent lever 136 with the said bar. The bent lever 136is pivoted at 137 and is actuated b the link 138 described above. It -isalso f drmed with a curved slot 140 in which works slidably a pin 141 onone end of the link 135. The link 135 is connected to the pointer 132 bymeans of the link 143 pivoted at 133. It will be understood that whenthe pointer 132 isadjusted for various latitudes, the link 143 moves 135about the end remote from the pin 141 and causes this in to move in theslot of the lever 140. ence the combined course and speed correctionstransmitted to the bar 120 by the link 135 have superimposed on them thelatitude cosine correction.

In order to introduce the plus or minus tan ent of latitude correction,the link 135 is ormedin two relatively slidable parts 144 and 145, thelatter being formedwith the transverse curved slot 146, and alongitudinal lot 147 while the former isformed with a pluralityof pins148 engaging in said slot 147 so as to hold the two parts in alignmentand at the same time permit longitudinal adjustment. Also the link 143is formed with a bent arm having a pin 147 thereon engaging in the saidslot 146. In this way any latitude adjustment of the pointer 132 causesa lengthening or shortening of the compound link 135 and the shape ofthe slot 146 is such that this lengthening or shortening introduces acorrecting movement proportlonal to the tangent of the north or southlatitude respectively.

From the foregoing it i evldent that all the various correctionscorresponding to different factors of travel of the ship or othervehicle are combined into one movement, which is impressed on the bar orcorrection device 120. This bar i shown as furnished with a pointer 150co-operating with a scale 500, so that the total correction to beapplied to the main compass reading can be ascertained merely byinspection. no calculations or reference to tables being necinsiiessary:'ihe bar *120-istshown asnconnected': to the shiftable 'lubbenslineninde'ataM;hy espeedrand-ricourse adjustments will impart movement?toe link 47 by 1 means .of Linkh26 a 1 means of legs 152.

In order thatthe corrected readings may 6 "be transmitted to one or moredistant repeater compasses, bar 120 maybe formed as a rack 153, theteeth ofwhich gear. with;

the -pinion 154 .forming part of a commutator switch such as hereinafterdescribed 10 for transmitting the corrected readings.

My preferred formof mechanism for ac: comphshing this result, however,is shown in Pi 1, 2, 3, 6' and 7 in which 20- is a rotata .le dischaving a knurled knob 21 thereon. Said disc is mounted in a secondrotatable disc or cup 22 and bears on its under surface a spiral slot23, Disc is,

provided with peed the on 22 is provide with index 28, (see 20 Fig. 3The said cup has also therein a curved slot 24,'while a pin 25 on a link26 works in both the slots 24 and 23. Secured to said cup is an arm 29journaled at 30 in a fixed bracket 31. The said arm is ro- 25 vided witha roller 32 adapted to be guided in a track guideway or cam ring 33secured to the rotatable card 1. Said link 26 is pivoted adjacent itsother end to a small bell crank lever 34 pivoted at 35 on a disc or 30cup 36 similar to cup 22. The other end of sand lever 34 carries a in 37which works in slot 38 in said disc. he said disc 36 may be providedwith a bracket 40 secured thereto and journaled in a fixed bracket 41for 35 the purpose of providing the disc with a bearing. Rotatablymounted within a depression in said disc is a second disc 41 having aknob 42 thereon and slots 43 and 44 therein. Said pin 37 engages thelast named lo/slot through the slot 38 in disc 36. Disc 36 also containsa slot 45 in which is slidably mounted a pin 46 on lever 47, said pinalso engaging the double M shaped slot 43. Lever 47 is shown as pivotedadjacent 45 its other end to a gear ector 151 pivoted at 51 to the fixedframe. Said gear sector meshes with an annular gear 52 (see Fig.

3) so that as the sector is oscillated the annular gear is rotated andcarries with it ring 14 to which it is attached.

It will readil be seen that, with the proper layout 0 the slots 23 and24, adjustment of knob 21 will move the link 26 an amount proportionalto the speed of 55 the ship. This speed is resolved in the directionofthe heading of the ship automatically by means of cam ring 32 and arm'29, which turn cup 22 and disc 20 together. correspondingly it will beseen that adjust- 6O ment of knob 42 will move lever 47 an amountproportional to a function of the latitude of the ship. Also that thefirst named quantity (i. e., the proper function of'the ships velocityor combined speed and heading) will be multiplied (or diraduations- 27while videdy by the second since movement 3f the- It should be notedthatthe velocit adjust: ment will not throw out the latitu e adjustmenta material amount since both the lati- 'tude': discs-are turned togetherby the adjustment of the velocity and hence the readmg of thegraduations 55 on the index 56 is not altered. The bell crank lever 34together with the slot 38 and 44 are provided to add to the result afunction (tangent) of the latitude indicated by the equation. Themarkings 15 on thering 14 may be read in connection with a fixed scale500' to show the correction applied as well as on the compass card.

In connection with the repeater compass,

I may if desired, provide an electro-magnetic evice 60 adapted to assistin the setting of the instrument from -a distance. When excited theelectromagnet 61 attracts armature 62 so that the finger 63 thereon willengage a notch 64 in a collar 65 on the. motor shaft when it is rotatedunder the The electro-magnet is preferably placed in circuit withcontacts 66 and 67 on a stationary part and on the rotatable card 1respectively in addition to being placed in circult with the actuatingcircuit closure 160 near the master compass so that the card will alwaysbe locked in a predetermined position.

As above stated the master compass from which said repeater is actuatedis illustrated more or 1cm digrammatically in Fig. 4. In said Fig., 73represents the casing of the gyroscope proper which is suspended orsupported from a follow-up member 68 rotatably mounted within frame 168.The said .gyroscopic unit is preferably provided with an upwardlyextending post 69 carrying a brush or trolley 70 which rolls on alurality of contacts 71 and 72 secured to t e follow-up member. The saidcontacts control .110 a reversible motor 79 geared through reducinggears 80 to gear 81 on the follow-up support, (see Fig. 8).' By this orsimilar means the member 68 is maintained in the same position inazimuththat the gyroscopic unit maintains. The aforementioned transmitter 8 ispreferably geared to said gear 81 through pinion 82.

Referring'now to Figs. 2, 3, 5 and 8, the same formof correction deviceis illustrated 12 in these figures as in Figs. 1,6 and 7. According tothismodification, however, the repeater card 1' is driven from areversible motor 85 instead of from a ste -by-step repeater motor, thesaid motor being placed in circuit through a relay 200 with reversingcontacts 70' 71' and 72' on the master compass 2. The said motor maydrive the card 1' through reduction gearing 86 similar in form to thatemployed with repeater mo- 130 tor 7. The said card may also beprovided; with a gear 87 and has connected thereto a ring33similarinformtothering33. Said gear87servestodriveoneormoretranmnitters 8' and 89through pimons 90 thereon. Transmitter 89 is shown as fixed to theeasing 91 of the repeater compass so that it will trananit the truemovements of, the compas dial. Transmitter 8' on the other hand is shownas mounted on the shiftable luhbers 14' so that it willtransmitthecor'rected r e ifiings of the compas. Transmitter 89 isplaced incircuitwitharepeaterfmotortil adapted to drive directly orindirectly the follow-up support 68' of the master comf-t. m ifiir 'f tryingpinion94"wit e 81' on said support. 8 is adapted to drive oneor-rnore repeater motors 100 '(Fig; 8) insimplified repeater compass orcompasses 100' so-that each repeater compas will indicate-thecorrectreading. Said motor maybe in all respeas identical with motor 7and is illu:rated as driving the repeater card 200,-

201 and pinion 202. From said transmitter, I may also drive a repeatermotor 101 on the master compass. Said motor is thro h beveled gears 102to one armr103 of a differential gear train 104. The 0 wposite arm 105of-sai'd train may be similar y driven by bevel rs 102' fromsaidrepeater motor 93 (see ig. 10). The central arm 106 of said train isprovided with an annular spur gear 107 which medics with gear sector108. saidsectorisrownasapartofabellerank lever 109 pivoted at 110, the uingarm of which carries a second gear sector 111 which meshes with anannular gear- 112 on, the under surface of the driftable lnbbers linoring 113. r V

Itwillreadilybesecnthatb meansof this difierential gear train, theuhbersline ring 113 will be moved an amount equal to the diflerencebetween the movement of tranmniflzers89and8'orinotherwords, an amountequal to the movement of shiftable lubbers line 14" so that the correctreadingswillalsobeshownonthemaster com-' The operation of the preferredform of m invention is as folows: repeater compass shown in Fig. 2 tonhavmg been connected up with. master pic com same re trve position 1nazimuth, since reversible motor 85 will not only actuate the of the shipand the approximate latitude. 4. The combination with a gyro-compass 130repeater card, but also trarmmitter 89, thereby causing the follow-upmember 68' of the compass to follow the gyroscope 73 by means ofrepeater motor 93.

In order set the correction device, the navigator simply turns the knobs2142 until the respective dials register the speed "principle ofwillretain the haliagealreadydmcr'ibedsothatthecorrected headingof theship provisions of the patent statutes, I have herein described the '5separation of m icrlrlviution, togather th apparatus,w i now consrde'rto represent the best embodiment thereofihutldesiretohaveitunderdaoodthat the apparatus shown is oul illustrative and that the invention cancarried out 1) other means. 'Also, while it isdetousethevariousfeaturesandelemeats in the combination and relatiorm described,someofthescmaybealteredand others omitted without interferingwith the more generhl results outlined, and the invention extends'tosuch use.

Having described my invention, what I claim and desire to secure byLetters Patout is:

1. In -navrgatr' 'onal a paratus, an azimuth indicator including-a rrotatable about an axis and a relatively stationary member conjointlyreadable, means eccentricmsaidarisandcarriedbysaid rotatable member andmechanism actuated by means 1' I l i member to correct the of theindiml'in ml 2. gyro-navigatio apparatus, an azimuth indicatorincludinga member rotatable about an axis, means eccentric to saidaxisandcarriedbysaidrotatablemember,a device for correct the apparentreadings of the indicator, an mec Sfl ld means for operating saidcorrecting device.

3. The combination with a gyro-com and electrical transmittingtherewith, of a regater compam comprising a motor therein 'ven from saidmeans, a card driven by said motor, a shiftable reference index for saidcard, and mechanism ac tuated by rotation of the card for shiftingsaidindex.

willbeobtained. ."If the ship shouldhrrnrnaaimuth there- -peater card 1'will be turned'also, and

said mtionary actuatedby' PI- amuse- 1 'havinga compass index and atransmitting means associated I ,3 said com"asses and interposed betweenthe reference index for m r. card, ashiftablerefereiice therewith,-of arepeater compass comprisin a motor controlled from said means, arepeater card driven by said motor, a shiftable anismactuated by herotation of the repeater card for shifting the repeater 'index andelectrical means connecting said referro com ange' 1n ence index withthe index on the passfcr causing a corresponding its position. i I a 5.In gyro -ships, a gyro-compam comprising. a gyroscopic element, afollow-up member, reversing contacts actuated by the relative move-.ment of said element and member, a reversible motive means actuatedfrom said contacts, a course indicator driven thereby, a transmitteralso driven by said motor, a shiftable indexfor said indicator, meansfor shifting said index, a second transmitter mounted so as to receivethe combined movements of said indicator and index and compass to causerotation adapted to actuate other repeater compasses, and arepeater-motor mounted on said gyroof said follow-up member and incircuit with said first transmitter.

6. In gyro navigational apparatus for ships, a gyro-compass comprising agyro scopic element, a follow-up azimuth indicating member, a shiftableindex therefor, re-

versing contacts on said element and member, a reversible motive meansactuated a course indicator driven from said contacts,

said

thereby, a transmitter also driven by motor, a shiftable index for saidindicator,

means for shifting said index, a second transmitter mounted so as toreceive the combined movements of sand indicator and mdex and adapted toactuate other repeater compasses, a repeater-motor mounted on saidgyro-compass to cause rotation of said follow-up member and in circuitwith said first transmitter, and a second repeater motor mounted on saidcompass and in circuit with said second transmitter, and meansinterconnecting said two motors and the rocompass index for causing itto repro uce the movements of the indicator index.

7 In gyro-navigational apparatus, a gyrocompass comprising a gyrosoopicelement, a

follow-up element, cooperating reversing contacts actuated by therelative movement of said two elements and a repeater motor for drivingsaid follow-up element, in combination with an independent repeatinginstrument comprising a reversible motor driven from said contacts, anda plurality of transmitters driven therefrom and adapted to drive saidrepeater motor and other repeater instruments.

8. In a navigational system, the combination with a master compass, of arepeater id repeater card, mech- G! "a a a "plred' navigationalapparatus for.

indicators,

said comprises and interposed betweenthe same for introducing acorrection to be ap- V to-the readings of the repeater comass. p 10. Ina repeating system, a sending instrument comprising a air of rotary1ndi-- cators, a transmitter V and a second transmitter driven driven byone of said by the combined movements of the two indieators, incombination with a master compass comprising a repeater motor drivenfrom each transmitter, an indicator driven from one of said motors'difierential connections between saidtwo motors and a cooperatingindicator driven from said connections.

11. The combination with a directionresponsive instrument having aprimary element and a follow-up element, of reversing contacts actuatedby said elements, a reversible motor electrically connected thereto, acorrection mechanism, a transmitter driven from said motor andmechanism, a repeater motor carried b said instrument and connected withsai transmitter, said transmitter being also adapted to drive one ormore repeater compasses.

12. In a enavigationalsystem, the combination with a master compass, ofa repeater compass electrically actuated therefrom, and a correctiondevice separate from both of said compasses and interposed between thesame for introducing a correction in accordance with the heading andspeed of the ship.

13. In a navigational system, the combination with a master compass, ofa reeater compass electrically actuated there- ?rom, and a correctiondevice separate from and interposed becorrection speed and both of saidcompasses tween the same for introducing a in accordance with theheading, latitude of the ship.

14. Thecombination with a gyro-compass, having a sensitive element of afollow up device therefor, transmitting means operate by relativemovement'between said element and device, a correction repeater operablerepealzngnotor .lotuaied by on of said'tnnsnlif-ters madings to thenefor transmitting corrected pegter compass.

follow said element. shil'f. In gar-navigational ay'pa'ntm for ps, agyro-comm con; rising a gyrosoopic element; n follow-u; munber, contactsoperated. by relative element and m a reversible motive means wtnatpdfram said more transmitters driven by was and connected to to causa itto follow said elomezfiat least dnve one or more re and 1'8. Thecombination" compas adapted to p of a sensitive seopic compass mountedfor a verticnl axis, a follow-n com with a.

. i I i m Inducing-said Ulreoted mdlcatlons. testimony whereof I havellflixod my g controller operated by mlatiw mgtion'dfsfid element andmembar tboiit. sun by snid nnlitmller, a said slid bar toeausa it tofollow said elqmant, said ins; a reversible motiv means actuaha m, 't ia mpeater m r actual; .35

tamingand connected to said mam to drum one or means, rqdnoe amidindwations; means means; connecting means hempmducing means-and said mfling means, whereby the retransare automnticul-ly corindications of thellfihldl;

y and ELMER A. SPERRY.

tatibly mounted about said axis adjaeentsn

